Posted on 01/31/2020 10:16:31 AM PST by cann
Russian scientists have published a concept for a new kind of nuclear reactor. It’s a hybrid reactor, meaning it includes both fusion and fission, and it runs almost exclusively on thorium instead of more volatile uranium. In computer simulations, the research team found its novel design of an “energy-generating blanket” could still produce high power with a relatively small footprint and not much radioactive waste.
There’s a lot to like about this design, including how it offers interesting middle-ground solutions in terms of fuel, reactor configuration, and safety. Thorium is one of the most abundant elements of its kind—more abundant than tin, which is so common and accessible that it’s one of the classical elements of alchemy. Uranium isn’t the rarest element in nature, but little of it is “available” in a common or affordable sense. If uranium were an asset, it would be a long-term CD with a penalty for convenient withdrawal.
In the hybrid thorium setup, thorium-plutonium pellets power a high-temperature, gas-cooled reactor. The paper doesn’t specify the gas, but existing coolants include carbon dioxide and helium. Gas-cooled reactors have always offered a way for reactors to make power using un-enriched, regular old uranium, making it more affordable and accessible to more countries. A hybrid reactor running on thorium could fill the same space.
A traditional nuclear reactor runs in critical state, but the hybrid thorium reactor instead operates in near-critical state. Instead of having a chain of neutrons produced by critical reaction, neutrons continue to pour in from a separate source. A magnetic field inside the reactor holds the powerful cloud of ionized gaseous deuterium plasma, which is the fusion part of the fusion-fission reactor. From there, neutrons spill out into a part the scientists call an “energy-generating blanket.” It’s this blanket where subcritical fission takes place, using neutrons from inside the plasma-filled magnetic tube.
The reactor itself is relatively small, with the plasma chamber measuring 12 meters in length. And by combining a fusion reaction with a fission one, the reactor maximizes efficiency. Compared with developing technology like the tokamak, this design could be much more down to earth, with less ramp-up time to performance and less volatility once it’s engaged.
Not really “new” technology... molten salt/thorium reactor theory has been around for decades. They also have “walk-away” safety. If all operators simply walked away a “plug” melts and all the radioactive material simply drains into an underground chamber and cools to become a non-radioactive blob of slag. Rickover opted for enriched uranium instead of the molten salt technology because you can’t make weapons of molten salt.
From your link:
Generally, smaller power lines mean bigger relative losses. So even though electricity may travel much farther on high-voltage transmission lines – dozens or hundreds of miles – losses are low, around two percent. And though your electricity may travel a few miles or less on low-voltage distribution lines, losses are high, around four percent.
“Distribution Sector considered as the weakest link in the entire power sector. Transmission Losses is approximate 17% while Distribution Losses is approximate 50%.”
This is referring to the weakest link. Of the total Losses, distribution is the weakest accounting for 50% of the losses, NOT 50% loss of transmission.
Yep. It’s pretty obvious that the author understands none of this and is essentially copying a press release. Somebody is going to have to do some real tap-dancing to convince me that this thing generates power through fusion.
Still a clever design, and might be able to be engineered without the Plutonium or U-235, although that's unlikely.
That’s what I’m thinking. If it’s that easy to get fusion power, who gives a crap about the rest of the device?
I am no scientist, but if you have what appears to be sustainable fusion, why do you even need the fission part of the process? I know I am missing something.
Yeah, clothes pins rank right up there with duct tape for being high tech. LOL
“this thing generates power through fusion.”
It is a CONCEPT!
” Rickover opted for enriched uranium instead of the molten salt technology because you can’t make weapons of molten salt.”
FAKE NEWS!
“That’s what I’m thinking. If it’s that easy to get fusion power, who gives a crap about the rest of the device?”
They are NOT getting fusion energy. Fusion is a source of neutrons.
D-D fusion is a tabletop curiosity (eg ICF reactor)which requires more energy input than output, but it produces neutrons. Not self sustaining tho. But if scaled a bit the neutrons can be captured by thorium eventually resulting in fissionable U-233. The resulting fission will exceed breakeven by quite a bit, and the fission produces extra neutrons which permit scaling to higher efficiency. Also I notice the lifecycle to U-233 produces some high energy electrons (beta) which could conceivably be utilized to improve the fusion.
We dreamed that if we got enough deeds to make a square foot, some day we could go there and stand on it; and just maybe there would be gold on it.
Innocent dreams, innocent times.
They might want to dedicate more than a one-liner to that CONCEPT, it’s kinda the key to the whole thing.
“They might want to dedicate more than a one-liner to that CONCEPT, it’s kinda the key to the whole thing.”
ROTFLMAO!
Thy did!
Hit thorium for a time period and then rotate that batch out. Chemically separate the non-thorium materials generated by the neutron exposure. The isolated protactinium content will decay to a fissionable uranium isotope. Easy peasy.
That said, this chemical reprocessing of hot materials is one of the difficult points to overcome for a salt based reactor with thorium as the fertile material. We could build a fast neutron version of a molten salt reactor which would burn spent reactor fuel and stored waste for many decades, without need for a thorium breeder.
Fast neutrons generated from a stand-alone source can split U238.
Fusion component generates neutrons without generating an abundance of energy.
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